1. Field of the Invention
The present invention relates to a Radio Frequency (RF) coaxial connector, and more particularly to a female RF coaxial connector used for mating with male RF coaxial connectors which are of various different diameters of inner conductors, due to the different types of coaxial cables selected for use, while maintaining consistent mechanical and electrical properties over a significant number of mating cycles.
2. Description of Related Art
The technological advancement has been calling for broader bandwidths for the RE equipment. As a result, the RF coaxial connectors, either on the coaxial cable ends or on the PC boards of signal devices, play a more and more important role in signal input and output. The characteristic impedance of a RF coaxial connector must match that of the signal source device when a broadband signal is transmitted so as to obtain a minimum return loss and attenuation.
As shown in FIGS. 1 and 2, a known conventional RF coaxial connector has a hollow outer conductor (1) inside which a dielectric insulated inner conductor (2) is concentrically installed. The inner conductor (2) consists of a rear end (21) and front end (22). The diameter of the rear end (21) is bigger than that of the front end (22). An insertion hole (210) is provided at the rear end (21). The insertion hole rim (211), being slit and crimped for spring and retention capabilities, will accept and secure firmly the coaxial cable center conductor (C1) which has a slightly larger diameter than the inner diameter of the crimped insertion hole rim (211). As known to us, however, different types of coaxial cables (C) have different diameter sizes of cable center conductors (C1) ranging from 0.5 to 1.2 mm for example. The known conventional RF coaxial connector is designed for mating only with a specific diameter of the coaxial cable center conductor. Various coaxial connectors with different specifications are required for accepting various different cable center conductor diameters, which is not an ideal practice for users.
For improving the aforementioned RF coaxial connector, a modified version of RF coaxial connector using an inner clip fingers inside the insertion hole as displayed in Taiwan patent NO. 304,636 is brought out. The modified RF coaxial connector, according to the patent, declares that it can work with many different sizes of coaxial cables. Since different sizes of coaxial cables have different sizes of cable center conductors, an issue does not come out if the RF coaxial connector were used on a small size cable center conductor (C1) at the first time and on a larger size one at a later time. But if it were used on a large size cable center conductor (C1) at the first time, the inner clip fingers inside the RF coaxial connector inner conductor will flare out and will not recover back to its original shape due to elastic fatigue. As a result, an intermittent signal transmission or electrical continuity failure might be experienced when it is next used on a smaller diameter cable center conductor later on.
Both of the aforementioned two kinds of RF coaxial connectors intrinsically utilize the same slit-and-crimp method for the inner conductors. Besides the elastic fatigue issue, this method is difficult and time-consuming for production.
The main objective of the present invention is to provide a female RF coaxial connector with an inner conductor mechanism that is capable of mating with various different diameters of center conductors of various different coaxial cables while maintaining consistent electrical and mechanical properties over a significant number of mating cycles.
To actualize the objective, the present invention of the RE coaxial connector has a hollow outer conductor inside which a concentrically positioned and dielectric insulated inner conductor is installed. The inner conductor features an interface end insertion hole inside which an elastic element and a U-type cylinder are installed. The outer wall of the U-type cylinder physically contacts the inner wall of the insertion hole of the inner conductor for electrical continuity. The elastic element sits right under the bottom of the U-type cylinder providing the U-type cylinder with extended travel distance for accepting various different cut lengths of the coaxial cable center conductors while maintaining solid electrical continuity between the cable center conductor and the connector inner conductor. The inner diameter of the U-type cylinder is specially designed for accommodating different diameters of center conductors of different coaxial cables, which is convenient for users to choose and replace with different coaxial cables from time to time.